Saturday, 24 October 2015

The following post offers a brief discussion of some of the oxygen isotope evidence for long-distance contact and migration between Britain and other parts of the world in the early medieval period and before. The particular focus here is on those individuals excavated in Britain whose results are above the expected range for people who grew up on these islands, indicating that they could well have spent part of their childhood in southern Iberia and/or North Africa.

The evidence used below primarily derives from recent research into the British oxygen isotope data retrieved from archaeological human dental enamel. The key principal underlying the utility of this material to archaeologists and historians is the fact that both phosphate oxygen isotope values (δ¹⁸Op) and structural carbonate oxygen isotope values (δ¹⁸Oc) of excavated teeth reflect the isotope composition of the drinking water (δ¹⁸Odw) that the individual consumed in their early years, when their teeth formed. Given that the local oxygen isotope composition of drinking water varies widely across not only the British Isles but also Europe and North Africa, reflecting variations in local climate and elevation, this means that oxygen isotope analysis has the potential to allow archaeologists to identify people who grew up outside of Britain with a far greater degree of confidence than was previously possible.(1)

The above is undoubtedly of considerable importance for the history of long-distance contact and movement between Britain and other parts of the world, and the focus in what follows is on the potential use of such material for identifying people who may have moved to Britain from southern Iberia and especially North Africa. There are two main reasons for such a focus. First and foremost, contact between Britain and this area is a recurring topic of interest for this blog, and the oxygen isotope evidence offers another possible window on such contacts in the early medieval period and before.(2) Second, people brought up in southern Iberia and North Africa can have notably higher oxygen isotope values that those brought up in Britain, unlike those brought up in France and the Netherlands, for example, where the drinking water oxygen isotope range is similar to that found in Britain. Needless to say, this makes their identification in the British archaeological record potentially somewhat easier.(3)

What follows offers a look at some of the sites that include burials of people whose dental enamel oxygen isotope results are at the highest end of the British range and beyond and so are potentially migrants to Britain from southern Iberia and/or North Africa, starting with the early medieval era and working backwards to the Bronze Age.

Early Medieval South Wales

A survey of dental enamel recovered from four early medieval cemeteries in South Wales reveals at least twelve individuals spread across three of the cemeteries who have oxygen isotope values above the upper end of the British range, representing more than a third of the total number of individuals investigated from these burial grounds.(4) Four of these people are defined as 'marginal', having results only just above 18.6‰ δ¹⁸Op, the conventional upper cut-off for phosphate oxygen isotope values from the British Isles, and so could possibly still represent people who grew up on the extreme western coast of Ireland, the Outer Hebrides or the Lands End area, where δ¹⁸O drinking water values are at their highest (-5.0‰ to -4.5‰ δ¹⁸Odw). The other eight individuals, however, have what are described as 'notably enriched δ¹⁸Op values', clearly above the conventional δ¹⁸Op upper cut-off for Britain and reflecting the consumption of water with δ¹⁸Odw values noticeably higher than the maximum British level of c. -4.5‰, and five of them moreover have very significantly enriched values, indicative of their childhood consumption of drinking water that had δ¹⁸Odw values ranging up to a maximum of around -3.3‰, well over 1‰ above the highest values found in Britain. In this context, it is worth noting that water oxygen isotope values above the British range and between-4.5‰ and c. -4.0‰ appear only to be encountered in Europe in small areas of south-east and south-west Iberia and are otherwise restricted to North Africa or further afield. Values between -4.0‰ and -3.5‰ are again found in North Africa but are even rarer in Europe, being only reported from a small area around Cádiz, southwest Spain, where groundwater values as high as -3.5‰ have been noted, whilst even higher values up to 0‰ and beyond are encountered only in Africa and Arabia.(5) As such, the above oxygen isotope results from early medieval South Wales are clearly of considerable potential interest to historians and archaeologists.

The geographic distribution of areas outside of the UK with rainwater oxygen isotope values above ‑5.0‰, shown in dark blue; all twelve of the people from South Wales discussed above consumed water with a δ¹⁸O level of c. ‑4.5‰ or higher (up to c. ‑3.3‰) in early life. Note, only 1% of the UK has δ¹⁸Odw water levels above ‑5.0‰, up to a maximum value of c. ‑4.5‰, but as the map shows, such levels are widely encountered throughout North Africa and in small areas of southern Europe. Levels above ‑4.0‰ are even more restricted in extent, being only recorded in Europe from a small area around Cádiz, southwest Spain, and are otherwise confined to North Africa, whilst levels above c. ‑3.5‰ are only known from North Africa and further afield. Image: C. R. Green, based on data from the sources cited in fn 3, especially Evans et al 2012 and Bowen 2003–15, utilising a Wikimedia Commons map of the Mediterranean region as a base.

With regard to the interpretation of this evidence, several points need to be made. First and foremost, it should be remembered that there is now a significant body of archaeological evidence that is usually thought to indicate the direct importation of goods from North Africa and the eastern Mediterranean into western Britain in the post-Roman period, probably beginning in the late fifth century AD and continuing into the sixth. The evidence for this consists of finds of Mediterranean amphorae sherds, used for transporting wine and olive oil, along with sherds of African Red Slip-Ware (ARSW) from the Carthage region and Phocaean Red Slip-Ware (PRSW) from western Asia Minor, with north-eastern Mediterranean material dominating the trade at first followed by surge in North African imports in the middle third of the sixth century AD. This material is primarily found at the important post-Roman high-status promontory fort of Tintagel, Cornwall, but it also occurs more widely throughout the south-west and along the western coast of Britain, including in South Wales, and is thought to have potentially arrived in Britain as a result of direct (and directed) imperial trade aimed primarily at procuring tin in the period c. 475–550.(6) Needless to say, this direct trade between the Mediterranean and Atlantic Britain supplies an obvious context for the apparent presence of migrants from southern Iberia and/or North Africa revealed by the isotopic material mentioned above, and it is indeed considered the most credible interpretation by the authors of the dental enamel survey.

Second, it is worth observing that three of the four cemeteries studied (Brownslade, Llandough and Porthclew) all included not only individuals with phosphate oxygen isotope results above the conventional British tooth enamel δ¹⁸Op cut-off of 18.6‰, but also that all three of these cemeteries actually included individuals with the very significantly enriched results indicative of the consumption of drinking water with δ¹⁸O values above -4.0‰, arguably most consistent with a North African origin. This obviously suggests that the long-distance movement of people from the Mediterranean to early medieval Wales was not an isolated event, something further supported by the fact that people with 'notably enriched' δ¹⁸Op results in these cemeteries formed nearly a quarter of all those tested, a very significant proportion indeed. Moreover, the possibility that migrant groups may well have been living in South Wales in the early medieval period is further heightened by the fact three of the individuals with notably enriched values were women and two were non-adults, implying the presence of families and further countering the idea that the post-Roman direct trade between the Mediterranean and Atlantic Britain was carried out solely by male, mercantile groups who stayed only for a brief period of time. Third and finally, it is interesting to observe that one of the people from Porthclew with a significantly enriched phosphate oxygen isotope value of 19.1‰, suggesting the childhood ingestion of drinking water with a value of c. -3.8‰, was radiocarbon dated to AD 680–900 (at 2σ). This dating is rather later than the period in which the maritime trade between South Wales and the southern Mediterranean discussed above was focussed, and it may consequently be suggestive of continued contact and movement between these areas even after the cessation of significant trading activity.(7)

Early Medieval Northumbria

An oxygen and
strontium isotope survey was undertaken on 78 individuals buried in the
seventh- to early ninth-century cemetery at Bamburgh (Northumberland), the 'royal city' of the
Anglo-Saxon Northumbrian kingdom of Bernicia. This revealed that over 50% of those
buried here have 'non-local' isotopic
signatures, indicative of them having spent their childhood in other areas such as Scandinavia, Ireland, western and southern Britain, continental Europe and North Africa. Such a degree of cosmopolitanism is credibly ascribed by the authors of the survey to the fact that the cemetery here was associated with the principal
pre-Viking royal centre in the north of England, and documentary and archaeological sources
certainly record the presence of people from Ireland, Scotland, continental
Europe and North Africa in Anglo-Saxon England.(8) With
regard to the specific results retrieved, there are 14 people buried in this cemetery who have isotope levels indicative of the
consumption of water with a value at or a little above the maximum
encountered in the British Isles, c. -4.5‰ (see above). and 3‰ or more above the oxygen isotope level of drinking water in the Bamburgh area, c. -7.5‰ δ¹⁸Odw. Even more interesting from the perspective of the present post,
however, are the seven men, women and non-adults—9% of the total—whose
oxygen isotope values are in fact significantly enriched beyond both the British range and the rest of the population of the cemetery, being indicative of the consumption of water with values ranging from -4.0‰ up to
-2.45‰ δ¹⁸Odw. As was discussed in the previous section, such
results are most consistent with an early life spent in
southwestern Iberia or North Africa, perhaps most plausibly the latter given
that three of these people had values reflecting δ¹⁸Odw between -3.2‰ and
-2.45‰, levels only encountered in North Africa or further afield.(9)

Bamburgh Castle viewed from Holy Island (image: Akuppa, used under its CC BY 2.0 license).

Roman Winchester

An isotopic survey of 40 individuals buried in the Late Roman Lankhills cemetery at Winchester revealed the presence of a significant number of probable non-locals, primarily from areas with higher drinking water oxygen isotope levels than are found in Britain or much of Europe. Eleven of the people tested in this cemetery have isotope results indicative of a non-British origin, with ten of these—25% of the total number tested—having values above the conventional upper cut-offs for oxygen isotope values from the British Isles (see above). As before, some of these have values only just above the latter level and so could conceivably still represent people who grew up on the extreme western coast of Ireland, the Outer Hebrides or the Lands End area, where δ¹⁸O drinking water values are at their highest. Others, however, have results that are notably enriched, and five have results indicative of the consumption of drinking water with oxygen isotope values from -4.0‰ right up to -2.8‰, the latter far above the British range and clearly implying an early life spent in North Africa.(10) Given this, it might well be wondered whether all those with values above the normal British range are not more likely to be of Mediterranean origin too, and a recent analysis of the thirteen people with the highest δ¹⁸O values from Lankhills, at or above the top of the British range, suggests that they form a discrete sub-group within the cemetery and that it is significantly more probable that they had their origins either in southern Iberia and/or North Africa than in the British Isles.(11)

Interestingly, the burial rites of the people with these extremely high results showed, in the main, no consistent pattern, confirming earlier observations that there is a mismatch in this cemetery, at least, between 'non-local' and 'local' burial rites and the actual origins of the people buried, contrary to previous hypotheses resulting from the original 1967–72 excavation of part of the Lankhills site. However, it is perhaps worth noting that one of the people with oxygen isotope results that were enriched above the usual British range was buried with two rare North African unguent flasks. Similarly, the individual with the very highest results, equivalent to -2.8‰ δ¹⁸Odw, has cranial characteristics that are suggested to be consistent with an origin in Egypt, and another person with oxygen isotope values above the conventional British cut-off has cranial characteristics said to be indicative of a 'Black' or 'Asian' origin. Finally, it is also important to note that the people with significantly enriched values were once again not exclusively male, as has sometimes been assumed to the case for early migrants—indeed, four of the five with the highest results were all female.(12)

North African unguentaria from Grave 82 at the Late Roman cemetery, Lankhills, Winchester (image: Oxford Archaeology, reused under their CC BY-SA 3.0 license).

Roman York

Isotopic analysis has been undertaken for a number of cemeteries from Roman York. One is the extremely unusual all-male cemetery at Driffield Terrace, York, where more than half the individuals interred had been decapitated. Teeth from eighteen individuals were sampled from 6 Driffield Terrace, three of which had oxygen isotope values at or just above the conventional upper cut-off for the British Isles and another of which had a result far above this, of 19.8‰ δ¹⁸Op, indicating the childhood consumption of drinking water with a value significantly above -3.0‰. Similarly, the remains of 43 individuals from the Trentholme Drive and The Railway cemeteries at York were subjected to isotopic analysis. Five of these had oxygen isotope results above the British range and three moreover had values that were very significantly above this, indicative of the childhood consumption of drinking water with values of -3.12‰, -2.87‰ and -2.31‰, respectively.(13) As was noted above, drinking water with such enriched values as these is not encountered in Europe and is instead indicative of an origin in North Africa.

In this light, it is interesting to note that anthroposcopic/craniometric analysis was also undertaken for both of the latter cemeteries at York too, with 11% of the Trentholme Drive samples and 12% of The Railway individuals being considered very likely to be of 'African descent', whilst yet more are thought to have potential 'mixed' or 'black' ancestry, up to a possible maximum of 38% of the population buried at Trentholme Drive and 51% of the population in the higher-status The Railway cemetery. Two of the three individuals with the highest oxygen isotope results were assessed by these means, one of whom was identified as being of potential 'mixed' ancestry and the other of 'white' ancestry. Of those thought likely to be of 'black' ancestry, only a proportion were also subject to isotopic analysis. The majority of these had oxygen isotope results significantly above the local range at York, where some of the lowest results in Britain are found, but still within the theoretical British range, and the interpretation of these individuals is a matter of debate, just as is the case for the famous Late Roman 'ivory bangle lady' of York too, who is believed to be of 'black' ancestry but consumed drinking water in childhood with a δ¹⁸Odw value only just within the upper end of the British range. Drinking water δ¹⁸O values that might produce the results of all of these people can certainly be found in western or far western Britain and Ireland, but it should be recalled that they are also available in other regions of the Roman Empire, including along parts of the Atlantic coast of France and Iberia, in some areas of the European Mediterranean coast, and in North Africa too. As such, it must remain unclear whether these people might all represent 'second generation migrants', as the authors of the study suggest, or if some of them could be 'first generation migrants' who had simply spent their childhood in those parts of North Africa that have similar δ¹⁸Odw values to those found in parts of Europe and Britain.(14)

A re-erected Roman column at York; this once stood within the great hall of the headquarters building of the fortress of the Sixth Legion at York (image: Carole Raddato, used under its CC BY-SA 2.0 license).

Roman Gloucester

The teeth of 21 individuals were sampled from a first- to fourth-century AD cemetery at Roman Gloucester, ten from the main cemetery and eleven from a second-century AD mass grave. As at Winchester, a significant subgroup within both areas of this cemetery had clearly enriched oxygen isotope values when compared to both the expected local range for people brought up in the local area of the town and the British Isles in general. This subgroup numbers 6 or 7 people, representing 28–33% of the total subjects tested, all of whom have oxygen isotope values at or above the conventional upper cut-off for oxygen isotope values from the British Isles, with the majority of them having consumed significantly enriched drinking water with δ¹⁸O values above -4.0‰, implying a probable early life spent in either southernmost Iberia or North Africa. Moreover, the members of the subgroup also all had notably enriched δ¹³C results compared to the rest of the population of the cemetery, something that is credibly seen as resulting from an early consumption of plants grown in the Mediterranean region rather than Britain. Finally, it is worth noting that the group with enriched oxygen isotope results was once again made up of both men and women.(15)

Late Bronze Age and Iron Age Kent

An isotopic analysis of the teeth of 26 individuals from a Late Bronze Age–Middle Iron Age (eleventh- to third-century BC) cemetery at Cliffs End Farm on the Isle of Thanet, Kent, has produced some of the highest oxygen isotope values yet recovered from archaeological teeth in Britain. Drinking water in this part of Kent has an oxygen isotope value of around -7.1‰, with no significant change believed to have taken place over the Holocene, but it is clear that a significant proportion of the people buried in this cemetery had actually consumed water with much higher or lower values than this in their early life. A small number of individuals from this cemetery had, for example, δ¹⁸Op results indicative of consuming drinking water with oxygen isotope values between c. -5.0‰ and -4.5‰. People with such elevated results are perhaps unlikely to have spent their childhood in eastern Kent, although quite where they might have moved to Kent from is open to debate, as drinking water with these values is found in several areas including the extreme west of Britain or Ireland, southern Iberia, the heel of Italy, and North Africa. More clarity is possible, however, with a further five individuals from this cemetery—19% of the total number investigated—who had results suggesting that they grew up in areas where water oxygen isotope values were even higher, above -4.0‰. Such levels are only really encountered in the extreme south-west of Iberia (around Cádiz) and in North Africa, and four of the people in question moreover had results indicative of consuming drinking water with levels above -3.0‰, well above those encountered anywhere in Europe and clearly implying an early life spent in North Africa.(16)

With regard to the five individuals with the most highly enriched δ¹⁸O values, it is worth noting that they belonged to both the Bronze Age and the Iron Age phases of the cemetery, although the majority date from the earlier era. It is also intriguing to note that two of them—one interred in the Late Bronze Age (eleventh to ninth century BC) and one in the Middle Iron Age (fourth to third century BC)—have the highest δ¹⁸Op values ever recorded from Britain, c. 21.4‰. Such results reflect the consumption of drinking water with an oxygen isotope value of around -1.0‰ to 0‰, which is far beyond anything known from Britain and probably indicative of a childhood spent in the Nile Valley, where equivalent δ¹⁸Oc values have been recorded from the ancient burial site at Mendes in the Nile Delta, Egypt.(17) Needless to say, this is of considerable interest. In terms of potential contexts for such long distance movement between the Mediterranean and Britain in the Late Bronze Age and Iron Age, previous posts on this site have discussed a variety of numismatic, archaeological, textual and linguistic evidence for contact between these areas in the pre-Roman Iron Age, including the presence of a Mediterranean anchor of potentially as early as the fifth century BC in Plymouth Sound. One might also point to the find of a North African Barbary ape skull from a probable third- to second-century BC context at Navan Fort, Northern Ireland, in this regard too. With regard to the Late Bronze Age, things area possibly a little less clear, unfortunately, although it is usually thought that there was movement along at least the Atlantic coast of Europe in this era and there are certainly a small number of possible Mediterranean items and anchors of this era that have been found off the southern coast of Britain and which may have some relevance here.(18)

A Sicilian strumento of c. 1200–1100 BC, found on the sea-floor at Salcombe, Devon, with other Bronze Age items from a probable twelfth-century BC shipwreck (image: British Museum).

Conclusion

Several key points emerge from the above summary of burial sites producing oxygen isotope evidence indicative of the presence of people from North Africa and southern Iberia in Britain between c. 1100 BC and c. AD 800, three of which are highlighted here by way of a conclusion. First and foremost, it is important to note that at least some migrants from these areas appear to have been present in Britain during all periods from the Late Bronze Age onwards. Whilst the presence of people from North Africa in Roman Britain is to a large degree unsurprising, as they are otherwise attested via literary and epigraphic sources, the fact that it can be shown that people from these areas were very probably also present in Bronze Age, Iron Age and early medieval Britain is a point of some considerable interest.

Second, the proportion of such individuals in each of the cemeteries surveyed is significant. For example, around a fifth of those buried in the Cliffs End prehistoric cemetery have oxygen isotope values probably indicative of such origins, as do around a quarter of those tested from the three early medieval cemeteries in South Wales and the Late Roman cemetery at Winchester, whilst at Roman Gloucester the proportion may be as high as a third. In this context, it is interesting to note that the anthroposcopic/craniometric analysis of two Roman cemeteries at York similarly points towards the presence of a potentially large number of people whose own or family origins lay in North Africa, with 11%–12% of those examined considered very likely to be of 'African descent', and yet others thought to have potential 'mixed' or 'black' ancestry, up to a possible maximum of 38% of the population buried at Trentholme Drive and 51% of the population in the higher-status The Railway cemetery. Of course, the sites and cemeteries surveyed here are likely to be to some extent exceptional, being located either at local capitals or close to the coast, but these results are nonetheless fascinating and certainly imply that some areas of Britain, at least, saw a degree of immigration from North Africa and/or southern Iberia in the early medieval period and before.

Finally, it is interesting to note that the potential migrants to Britain from North Africa and/or southern Iberia discussed above include men, women and non-adults, implying that contact between Britain and these areas was not solely the preserve of male mercantile or military groups, as has sometimes been assumed. Indeed, in some cases women and non-adults actually form the majority of the migrants identifiable there via oxygen isotope analysis, as is the case at Winchester and in South Wales.

Notes

1 On current approaches to oxygen isotope analysis and the underlying methodology, principles and issues, see, for example, J. A. Evans, C. A. Chenery & J. Montgomery, 'A summary of strontium and oxygen isotope variation in archaeological human tooth enamel excavated from Britain', Journal of Analytical Atomic Spectrometry, 27 (2012), 754–64 and Supplementary Material I (14 pp.), and C. Chenery et al, 'Strontium and stable isotope evidence for diet and mobility in Roman Gloucester, UK', Journal of Archaeological Science, 37 (2010), 150–63. The current post follows the interpretations and approaches to those individuals with notably enriched dental enamel oxygen isotope results adopted in these studies and also in other recent publications such as K. A. Hemer et al, 'Evidence of early medieval trade and migration between Wales and the Mediterranean Sea region', Journal of Archaeological Science, 40 (2013), 2352–59.2 See, for example, C. R. Green, 'Thanet, Tanit and the Phoenicians: place-names, archaeology and pre-Roman trading settlements in eastern Kent?', 21 April 2015, blog post, online at http://www.caitlingreen.org/2015/04/thanet-tanit-and-the-phoenicians.html; 'A Mediterranean anchor stock of the fifth to mid-second century BC found off the coast of Britain', 29 August 2015, blog post, online at http://www.caitlingreen.org/2015/08/a-mediterranean-anchor.html; and 'A great host of captives? A note on Vikings in Morocco and Africans in early medieval Ireland & Britain', 12 September 2015, blog post, online at http://www.caitlingreen.org/2015/09/a-great-host-of-captives.html.3 The current oxygen isotope range for drinking water (δ¹⁸Odw) in Britain and Ireland is around -9.0‰ to -4.5‰, with only 1% of the British Isles having values above -5.0‰, namely in the extreme south-west of Britain, the extreme south-west of Ireland, and part of the Outer Hebrides, a situation that is believed to have changed little between the Mesolithic and Medieval eras. This range accords well with the apparent local British range of phosphate oxygen isotope values from excavated teeth, which is usually agreed to fall between 16.6‰ and 18.6‰ δ¹⁸Op, although Evans et al have recently concluded that people brought up on the far west of the British Isles could potentially have values a little higher too, reflecting the degree of normal ambient variation that might be seen within populations exposed to the extremes of drinking water composition within the British Isles. Similar or lower drinking water oxygen isotope values, from <-10.0‰ to -5.0‰, are found across much of western Europe, as can be seen from the first map reproduced above. In contrast, southern Iberia has notably higher drinking water/precipitation δ¹⁸O values, from -5.0‰ up to a maximum of c. -4.0‰, except around Cádiz where drinking water values of up to c. -3.5‰ have been noted, and North Africa has values from the British range right up to around 0‰, with even higher values found in parts of Sudan (ancient Nubia) and Ethiopia. See further on Britain W. G. Darling et al, 'The O and H stable isotope composition of freshwaters in the British Isles. 2. Surface waters and groundwater', Hydrology and Earth System Sciences Discussions, 7 (2003), 183–95; J. A. Evans et al, 'A summary of strontium and oxygen isotope variation in archaeological human tooth enamel excavated from Britain', Journal of Analytical Atomic Spectrometry, 27 (2012), 754–64 at pp. 757–8 and Table 1; C. Chenery et al, 'Strontium and stable isotope evidence for diet and mobility in Roman Gloucester, UK', Journal of Archaeological Science, 37 (2010), 150–63 at pp. 153, 156–7, 160. On mainland Europe and Africa, see BGS/C. Chenery, 'Oxygen isotopes values for modern European drinking water' (map), online at www.wessexarch.co.uk/projects/amesbury/tests/oxygen_isotope.html; Evans et al, 'Summary of strontium and oxygen isotope variation', fig. 12; G. Bowen, 'Waterisotopes.org: global and regional maps of isotope ratios in precipitation', online dataset 2003–15, figures online at http://wateriso.utah.edu/waterisotopes/pages/data_access/figures.html; L. J. Araguas-Araguas & M. F. Diaz Teijeiro, 'Isotope composition of precipitation and water vapour in the Iberian Peninsula', in IAEA, Isotopic composition of precipitation in the Mediterranean Basin in relation to air circulation patterns and climate (Vienna, 2005), pp. 173–90 at fig. 3; M. R. Buzon & G. Bowen, 'Oxygen and carbon isotope analysis of human tooth enamel from the New Kingdom site of Tombos in Nubia', Archaeometry, 52 (2010), 855–68, esp. Table 2; C. White et al, 'Exploring the effects of environment, physiology and diet on oxygen isotope ratios in ancient Nubian bones and teeth', Journal of Archaeological Science, 31 (2004), 233–50 and Table 2.4 K. A. Hemer et al, 'Evidence of early medieval trade and migration between Wales and the Mediterranean Sea region', Journal of Archaeological Science, 40 (2013), 2352–59.5 See further the references cited in footnote 4, especially Evans et al, 'Summary of strontium and oxygen isotope variation', fig. 12, and Araguas-Araguas & Diaz Teijeiro, 'Isotope composition of precipitation and water vapour in the Iberian Peninsula', fig. 3. See also K. Killgrove, Migration and Mobility in Imperial Rome (University of North Carolina PhD Thesis, 2010), pp. 263, 280, 284–5, 310–11 who identifies the three people in her study of Rome who have oxygen isotope results indicative of consuming drinking water with a δ¹⁸O value above -4.0‰ as probable North African immigrants to the city, rather than European.6 See, for example, M. Fulford, 'Byzantium and Britain: a Mediterranean perspective on post-Roman Mediterranean imports in western Britain and Ireland', Medieval Archaeology, 33 (1989), 1–6; E. Campbell, Continental and Mediterranean Imports to Atlantic Britain and Ireland, AD 400–800, Council for British Archaeology Research Report 157 (York, 2007); E. Campbell & C. Bowles, 'Byzantine trade to the edge of the world: Mediterranean pottery imports to Atlantic Britain in the 6th century', in M. M. Mango (ed.), Byzantine Trade, 4th-12th Centuries: The Archaeology of Local, Regional and International Exchange (Farnham, 2009), pp. 297–314; T. M. Charles-Edwards, Wales and the Britons, 350–1064 (Oxford, 2013), pp. 222–3.7 Hemer et al, 'Evidence of early medieval trade and migration between Wales and the Mediterranean Sea region', 2357–8.8S. E. Groves et al, 'Mobility histories of 7th–9th century AD people buried at early medieval Bamburgh, Northumberland, England', American Journal of Physical Anthropology,
151 (2013), 462–76. The description of Bamburgh as 'the royal city' of
Bernicia is that of Bede, writing in the first half of the eighth
century (Historia Ecclesiastica, III.6). With regard to the documentary evidence for Africans in Anglo-Saxon England, see also Historia Ecclesiastica IV.1, where Bede describes Hadrian, the later seventh- and eighth-century Abbot of
St Augustine's, Canterbury, as 'a man of African race' (HE IV.1).9Groves et al, 'Mobility histories of 7th–9th century AD people
buried at early medieval Bamburgh', esp. pp. 465, 470 and Supplementary
Figure 7.10 P. Booth et al, The Late Roman Cemetery at Lankhills, Winchester: Excavations 2000–2004 (Oxford, 2010), pp. 421–8; H. Eckardt et al, 'Oxygen and strontium isotope evidence for mobility in Roman Winchester', Journal of Archaeological Science, 36 (2009), 2816–25.11 Evans et al, 'Summary of strontium and oxygen isotope variation', fig. 11 & pp. 760–2.12 Booth et al, The Late Roman Cemetery at Lankhills, pp. 249–51, 361, 509–16.13 G. Müldner et al, 'The ‘Headless Romans’: multi-isotope investigations of an unusual burial ground from Roman Britain', Journal of Archaeological Science, 38 (2011), 280–90; S. Leach et al, 'Migration and diversity in Roman Britain: a multidisciplinary approach to the identification of immigrants in Roman York, England', American Journal of Physical Anthropology, 140 (2009), 546–61.14 Leach et al, 'Migration and diversity in Roman Britain', Table 4 and pp. 546, 550–2, 558–9; S. Leach et al, 'A Lady of York: migration, ethnicity and identity in Roman Britain', Antiquity, 84 (2010), 131–45. On the isotopic values of water in North Africa, see for example Evans et al, 'Summary of strontium and oxygen isotope variation', fig. 12, and G. Bowen, 'Waterisotopes.org: global and regional maps of isotope ratios in precipitation'.15 C. Chenery et al, 'Strontium and stable isotope evidence for diet and mobility in Roman Gloucester, UK', Journal of Archaeological Science, 37 (2010), 150–63, who note that 'the probability of these [individuals] being from Britain is small and an origin abroad is more likely' (p. 158).16 The above is based primarily on J. I. McKinley et al, 'Dead-sea connections: a Bronze Age and Iron Age ritual site on the Isle of Thanet', in J. T. Koch & B. Cunliffe (eds.), Celtic from the West 2. Rethinking the Bronze Age and the Arrival of Indo-European in Atlantic Europe (Oxford, 2013), pp. 157–83, esp. pp. 166–8 and figs. 6.5, 6.6 and 6.7.17 The oxygen isotope values from the Mendes burial site in the Nile Delta, Egypt, are expressed as both δ¹⁸Odw and δ¹⁸Oc in Buzon & Bowen, 'Oxygen and carbon isotope analysis of human tooth enamel from the New Kingdom site of Tombos in Nubia', Table 2, and the latter can be converted to δ¹⁸Op using the equation in C. Chenery et al, 'The oxygen isotope relationship between the phosphate and structural carbonate fractions of human bioapatite', Rapid Communications in Mass Spectrometry, 26 (2012), 309–19. Needless to say, the δ¹⁸Op and equivalent δ¹⁸Odw values of the two people from Thanet fall within both the reported δ¹⁸Odw and the calculated δ¹⁸Op ranges for Mendes, and are moveover above the bottom of the range of δ¹⁸Op values for people who grew up in the Nile Valley (21.0‰) as reported in Chenery et al, 'Strontium and stable isotope evidence for diet and mobility in Roman Gloucester, UK', p. 158.18 On pre-Roman Iron Age contacts, see especially C. R. Green, 'Thanet, Tanit and the Phoenicians: place-names, archaeology and pre-Roman trading settlements in eastern Kent?', 21 April 2015, blog post, online at http://www.caitlingreen.org/2015/04/thanet-tanit-and-the-phoenicians.html, and 'A Mediterranean anchor stock of the fifth to mid-second century BC found off the coast of Britain', 29 August 2015, blog post, online at http://www.caitlingreen.org/2015/08/a-mediterranean-anchor.html. On the Barbary ape from Navan Fort, Northern Ireland, see for example I. Armit, Headhunting and the Body in Iron Age Europe (Cambridge, 2012), pp. 72–3, and K. A. Costa, 'Marketing archaeological heritage sites in Ireland', in Y. M. Rowan and U. Baram (eds.), Marketing Heritage: Archaeology and the Consumption of the Past (Walnut Creek, 2004), pp. 69–92 at p. 73. On possible finds of Late Bronze Age Mediterranean items from Britain, see for example S. Needham & C. Giardino, 'From Sicily to Salcombe: a Mediterranean Bronze Age object from British coastal waters', Antiquity, 82 (2008), 60–72, and D. Parham et al, 'Questioning the wrecks of time', British Archaeology, 91 (2006), 43–7, online at http://www.archaeologyuk.org/ba/ba91/feat2.shtml. A possible three-holed Bronze Age stone Mediterranean anchor from Plymouth Sound has been mentioned in news reports relating to the SHIPS Project/ProMare, but is as yet unidentified on the database for this project; see T. Nichols, 'Unique project launched to shed light on hidden treasures in Plymouth Sound', Plymouth Herald, 5 July 2014, online at http://www.plymouthherald.co.uk/Shedding-light-hidden-treasures-Sound/story-21332210-detail/story.html, although it should be noted that the dating and geographical origins of such stone anchors is open to debate.

About This Website

This is the blog of Dr Caitlin Green. Although my main academic research foci and publications are dealt with elsewhere, this blog will feature posts on these and other topics that I'm currently working on, including drafts of papers, ideas and similar—these are usually identifiable by the presence of footnotes. You're free to cite these drafts if they are of interest, and are reminded that academic blogs are indeed citable under most citation systems. In addition, the current site also houses posts relating to my personal interests, including landscape and coastal history, long-distance contacts, early literature and legends, and the history, archaeology, place-names and legends of Lincolnshire. For further details of this website & how to contact me, please see the 'About' page or @caitlinrgreen on Twitter.